Subject: [mobile-ip] Q about size of Kbu

From: Vladislav Yasevich <[email-masked]>
Date: Wed, 25 Sep 2002 12:02:23 -0400

Hi All

I was wondering why the size of Kbu is specified as 16 octets?

The Kbu is generated using a SHA1 hash with produces a 20 octet
result, but that result seems to be truncated to 16 octets and
I really can't find a good reason to do it.

So, can someone enlighten me please...

-vlad
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Vladislav Yasevich		Tru64 UNIX - IPv6 Project Lead
Hewlett Packard 		Tel: (603) 884-1079
Nashua, NH 03062		ZKO3-3/T07

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From: Jari Arkko <[email-masked]>
Date: Fri, 27 Sep 2002 01:26:33 +0300

> So, can someone enlighten me please...

I thought we had fixed the lengths of various cryptographic
entities already in draft 18, but apparently not... Kbu really
needs to be 20 bytes, because it is used as the key in the MAC
/ SHA1 function which requires a 20 byte key.

Jari